Pacific Gas & Electric Co., Northern California's largest power utility, called its first "SmartDay" of the year - asking certain residential customers to voluntarily reduce electricity use. The utility also called a "SmartDay" today. Typical conservation actions include operating laundry machines only in the cool morning hours and turning off or unplugging all unused devices and lights.

Customers who volunteer for the program get a rate break in exchange for reducing electricity use between 2 p.m. and 7 p.m. on hot summer days when electrical generation and distribution facilities are nearing capacity.

"When we know there is going to be a hot spell, we do ask customers to conserve," said Nicole Liebelt, a PG&E spokeswoman.

That said, the electricity system in California is more robust than it was in 2000 and 2001, Liebelt said. More than a decade ago, unscrupulous energy dealers took advantage of privatization to corner the market in California.

The state had widespread power outages as well as severe spikes in electricity rates.

"We have capacity to provide service to customers," Liebelt said.

The California Independent System Operator projected that demand for electricity statewide would peak at 41,942 megawatts today. (A megawatt is 1,000,000 watts, or enough power for 10,000 100-watt light bulbs.)

That's far less than California's record 50,270 megawatts peak electricity demand that occurred July 24, 2006. That spike happened during a 12-day stretch of 100-plus temperatures that killed several people in San Joaquin County and prompted local officials to open cooling shelters for people without air conditioning.

As bad as that heat wave sounds, it was only the third longest, according to weather records for Stockton Metropolitan Airport that date back to 1948.

The longest triple-digit heat wave was 14 days. It ended Aug. 2, 1980. The next worst was 13 days the following summer, National Weather Service meteorologist Jim Mathews said.

The odds for hotter- or cooler-that-normal temperatures for the rest of the summer, he said, appear to be about even. Last year, when Pacific Ocean waters off the coast were in a cooler-than-normal La Niņa pattern, California had heavy winter snowfall and a mild summer.

This year, Mathews said, the Pacific is in a neutral state - neither La Niņa or El Niņo.

Mathews said the heat wave that caused such misery in the eastern United States is now abating, allowing a more typical pattern to shift a high-pressure zone west to the Four Corners area of the U.S. And that means fairly average summer weather is likely in California.